公开(公告)号：US06421399B1

公开(公告)日：2002-07-16

申请号：US09035533

申请日：1998-03-05

申请人： Dan Avidor ,  Colin Alan Warwick

发明人： Dan Avidor ,  Colin Alan Warwick

IPC分类号： H04L2722

CPC分类号： H04L27/2276 ,  H04L2027/003 ,  H04L2027/0048 ,  H04L2027/0067 ,  H04L2027/0085

摘要： A frequency and phase estimator simultaneously estimates the frequency and phase of an MPSK modulated signal with a frequency uncertainty range on the order of the symbol rate. The estimator defines a plurality of contiguous bands within the frequency uncertainty range of the signal, estimates the frequency to one of the bands, and utilizes the frequency estimate to derive a phase estimate. In a preferred embodiment, a plurality of signal samples of the frequency shifted signal in each of said bands are accumulated to produce a vector for each band, and the frequency estimate is selected in one of said bands, based upon the magnitude of the corresponding vector. The phase is estimated from the argument of the corresponding vector. The present invention is particularly suited for burst modems or TDMA systems, where frequency and phase estimates must be derived reliably from a limited number of incoming symbols at the beginning of each burst.

公开(公告)号：US20020085651A1

公开(公告)日：2002-07-04

申请号：US09949069

申请日：2001-09-07

发明人： Jian Gu

IPC分类号： H04L027/06

CPC分类号： H04L27/2662 ,  H04L27/2657 ,  H04L27/2679 ,  H04L2027/0028 ,  H04L2027/0048

摘要： A frequency and timing offset adjustment system for a digital signal without changing the local oscillator frequency and the local sampling clock frequency. The frequency offset adjustment system includes a sine function look-up table, an interpolator, and an adjusting element. The look-up table provides sine sample values at an interval close enough to produce said sine sample values with sufficient accuracy, but far enough to enable reduction in size of the look-up table. For timing adjustment, a mechanism enables selection of an appropriate set of samples for a current symbol based on observation of accumulated timing error.

摘要翻译： 用于数字信号的频率和定时偏移调整系统，而不改变本地振荡器频率和本地采样时钟频率。 频率偏移调整系统包括正弦函数查找表，内插器和调整元件。 查找表以足够的间隔提供正弦样本值，以足够的精度产生所述正弦样本值，但足够大以能够减小查找表的大小。 对于定时调整，机制使得能够基于对累积定时误差的观察，为当前符号选择合适的采样集合。

公开(公告)号：US6072841A

公开(公告)日：2000-06-06

申请号：US886637

申请日：1997-07-01

申请人： Moe Rahnema

发明人： Moe Rahnema

IPC分类号： H04L7/04 ,  H04L27/00 ,  H04L27/233 ,  H04L27/227

CPC分类号： H04L27/2332 ,  H04L2027/0032 ,  H04L2027/0048 ,  H04L2027/0055 ,  H04L7/04

摘要： A method, and related apparatus, for coherently demodulating phase-modulated data which is coherently transmitted (i.e., without the use of differential encoding of the data) on Rician fading channels. The method uses phase unwrapping and phase interpolation, in conjunction with block phase estimation, to achieve a performance comparable with coherent detection of coherently transmitted data while reducing processing requirements.

摘要翻译： 一种用于相干解调在Rician衰落信道上相干发送（即，不使用数据的差分编码）的相位调制数据的方法和相关装置。 该方法使用相位展开和相位插值，结合块相位估计，以实现与相干传输数据的相干检测相当的性能，同时减少处理要求。

公开(公告)号：US5579345A

公开(公告)日：1996-11-26

申请号：US322847

申请日：1994-10-13

申请人： Brian W. Kroeger ,  Jeffrey S. Baird ,  Joseph B. Bronder

发明人： Brian W. Kroeger ,  Jeffrey S. Baird ,  Joseph B. Bronder

IPC分类号： H04L27/00 ,  H04L27/233 ,  H04L27/06 ,  H03D3/22

CPC分类号： H04L27/2332 ,  H04L2027/003 ,  H04L2027/0048

摘要： A carrier tracking loop that uses a frequency locked loop (FLL) and incorporates synchronized matched filters to minimize complexity of the system. The synchronized matched filters eliminate out-of-band interference while minimizing computation. The carrier tracking loop has an improved error signal generation to extend a frequency range and by employing error signal normalization, which extends the dynamic range of the amplitude of the input signal and allows the frequency to flywheel when signal fading occurs.

摘要翻译： 使用频率锁定环路（FLL）的载波跟踪环路，并集成了同步的匹配滤波器，以最大程度降低系统的复杂度。 同步匹配滤波器消除带外干扰，同时最小化计算。 载波跟踪环路具有改进的误差信号产生，以扩展频率范围并通过采用误差信号归一化，其延长了输入信号幅度的动态范围，并允许频率在发生信号衰落时飞行。

公开(公告)号：US5272446A

公开(公告)日：1993-12-21

申请号：US929588

申请日：1992-08-17

申请人： Harvey Chalmers ,  Farhad B. Verahrami ,  Ajit Shenoy

发明人： Harvey Chalmers ,  Farhad B. Verahrami ,  Ajit Shenoy

IPC分类号： G01R23/165 ,  H04L27/00 ,  H04L27/233 ,  H04L27/22

CPC分类号： H04L27/2332 ,  G01R23/165 ,  H04L2027/0032 ,  H04L2027/0048 ,  H04L2027/0095

摘要： A low-bit-rate, low-cost, all-digital preambleless demodulator for maritime and mobile data communications operates under severe high noise conditions, fast Doppler frequency shifts, large frequency offsets, and multipath fading. Sophisticated algorithms, including an FFT-based burst acquisition system, a cycle-slip resistant carrier phase tracker, an innovative Doppler tracker, and a fast acquisition symbol synchronizer, provide reliable burst reception. The compact DSP-based demodulator includes an input buffer receiving a complex sampled baseband input signal and providing a baseband output to a coarse frequency estimator fast Fourier transform (FFT) or discrete Fourier transform (DFT) module which produces a first estimation of the carrier frequency. A fine frequency estimator FFT or DFT module receives the first estimation and provides a second estimation of the carrier frequency. An extra coarse frequency estimator FFT or DFT module may be provided between the buffer and the coarse frequency estimator.

摘要翻译： 用于海事和移动数据通信的低比特率，低成本，全数字前导码解调器在恶劣的高噪声条件下运行，快速多普勒频移，大的频率偏移和多径衰落。 复杂的算法，包括基于FFT的脉冲串采集系统，抗周转滑移载波相位跟踪器，创新的多普勒跟踪器和快速采集符号同步器，提供可靠的突发接收。 紧凑的基于DSP的解调器包括输入缓冲器，其接收复数采样的基带输入信号，并向粗频率估计器快速傅里叶变换（FFT）或离散傅里叶变换（DFT）模块提供基带输出，该模块产生载波频率的第一估计 。 精细频率估计器FFT或DFT模块接收第一估计并提供载波频率的第二估计。 可以在缓冲器和粗略频率估计器之间提供额外的粗略频率估计器FFT或DFT模块。

公开(公告)号：US4977580A

公开(公告)日：1990-12-11

申请号：US256958

申请日：1988-10-13

申请人： John D. McNicol

发明人： John D. McNicol

IPC分类号： H04L27/22 ,  H04J3/00 ,  H04L7/00 ,  H04L7/02 ,  H04L7/027 ,  H04L7/10 ,  H04L27/00 ,  H04L27/227 ,  H04L27/233

CPC分类号： H04L7/0029 ,  H04L27/2273 ,  H04L27/2276 ,  H04L27/2332 ,  H04L2027/003 ,  H04L2027/0048 ,  H04L2027/0095 ,  H04L7/0274

摘要： The present invention provides a method of detecting the clock rate and recovering the carrier in a TDMA (time division multiple access) signal. The quadrature baseband components are stored for a predetermined amount of time as sampled data and the clock phase error of the baseband samples are estimated. The clock phase of the baseband samples are corrected from the estimated clock phase error by using interpolation over the sampled quadrature components. The carrier phase error of the stored baseband time corrected quadrature samples are then estimated and the carrier phase is corrected according to the estimated phase error. The corrected clock and carrier signals are then forwarded to decision circuit means for providing demodulated data.

摘要翻译： 本发明提供了一种在TDMA（时分多址）信号中检测时钟速率和恢复载波的方法。 将正交基带分量作为采样数据存储预定量的时间，并估计基带采样的时钟相位误差。 通过对采样的正交分量进行插值，从估计的时钟相位误差校正基带采样的时钟相位。 然后估计存储的基带时间校正正交采样的载波相位误差，并根据估计的相位误差校正载波相位。 校正的时钟和载波信号然后被转发到用于提供解调数据的判定电路装置。

公开(公告)号：US4694204A

公开(公告)日：1987-09-15

申请号：US706597

申请日：1985-02-28

申请人： Kazunori Nishijima ,  Mitsutoshi Sugawara

发明人： Kazunori Nishijima ,  Mitsutoshi Sugawara

IPC分类号： G06G7/163 ,  H03L7/087 ,  H04L27/00 ,  H04L27/227 ,  H03B17/00 ,  G06G7/16

CPC分类号： H04L27/2273 ,  G06G7/163 ,  H03L7/087 ,  H04L2027/0048 ,  H04L2027/0067

摘要： A transistor circuit for a signal multiplier used in, for example, a demodulator by means of the Costas loop method is disclosed. The transistor circuit comprises first to third circuit stages each including first and second transistors coupled in a differential form. The first to third circuit stages are connected in tandem with one another such that the output signal current of each circuit stage is supplied to the succeeding circuit stage without a substantial change. Further, each of the first to third circuit stages is supplied with one of or both of two input signals P and Q. As a result, the transistor circuit produces an output signal representing a signal multiplication: P.times.Q.times.(P+Q).times.(P-Q).

摘要翻译： 公开了一种用于例如通过科斯塔斯循环方法解调器的信号倍增器的晶体管电路。 晶体管电路包括第一至第三电路级，每个级包括以差分形式耦合的第一和第二晶体管。 第一至第三电路级彼此串联连接，使得每个电路级的输出信号电流被提供给后续电路级而没有实质变化。 此外，第一至第三电路级中的每一个被提供有两个输入信号P和Q中的一个或两者。结果，晶体管电路产生表示信号乘法的输出信号：PxQx（P + Q）×（PQ ）。

公开(公告)号：US4652838A

公开(公告)日：1987-03-24

申请号：US724309

申请日：1985-04-17

申请人： Edward J. Nossen

发明人： Edward J. Nossen

IPC分类号： H04K1/00 ,  H04L27/00 ,  H04L27/20 ,  H04L27/227

CPC分类号： H04L27/2014 ,  H04K1/006 ,  H04L27/2273 ,  H04L2027/0048

摘要： A communications system for conveying information angle-modulated onto a carrier includes a modulator which angle-modulates the data onto the carrier and which also randomly changes the phase of the carrier. Since the carrier phase is randomly changed, an unauthorized receiver or interceptor of the signal who frequency-multiplies the signal and integrates over a long period in order to reconstruct the carrier produces a carrier which has a broader bandwidth and relatively less amplitude than in the case in which the carrier phase is not randomly changed. The probability of intercept and demodulation by the unauthorized receiver is thereby reduced. The authorized receiver frequency-multiplies and integrates for the known frame interval to recover the carrier.

摘要翻译： 用于将角度调制的信号传送到载波上的通信系统包括调制器，其将数据角度调制到载波上，并且随机地改变载波的相位。 由于载波相位是随机变化的，所以信号的未经授权的接收机或拦截器频率乘以信号并且在长时间内积分以便重建载波产生具有比这种情况更宽的带宽和相对较小振幅的载波 其中载体相不是随机改变的。 从而减少了未经授权的接收机的拦截和解调的概率。 授权的接收机对已知的帧间隔进行频率乘法和积分，以恢复载波。

公开(公告)号：US3654564A

公开(公告)日：1972-04-04

申请号：US3654564D

申请日：1970-06-04

申请人： PHILIPS CORP

发明人： TISI FELIZ DANIEL ,  JAGER FRANK DE

IPC分类号： H04L27/00 ,  H04L27/227 ,  H03D3/18

CPC分类号： H04L27/2273 ,  H04L2027/0022 ,  H04L2027/0028 ,  H04L2027/0048 ,  H04L2027/0087

摘要： The invention relates to a receiver for the reception of information pulse signals transmitted by means of n-phase modulation wherein the original information pulses coincide with different pulses from a series of equidistant clock pulses, the receiver including an n-phase demodulator which is provided with a plurality of parallel arranged synchronous demodulators which are fed by carriers having mutually different reference phases originating from a local carrier generator which is stabilised in phase on the carrier associated with the received signals, signal channels being connected to the outputs of the n-phase demodulator including sampling circuits controlled by a local clock pulse generator the output signal of which sampling circuits characterizes the phase of the received carrier relative to the relevant reference phase of the local carrier at the instants of the local clock pulses, the receiver furthermore being provided with combination circuits connected to the sampling circuits, which combination circuits characterize each of the n-possible phase sectors of the transmitted signals in a phase diagram by means of a separate combination of the outputs of the signal channels. Such receivers are advantageously used in transmission systems which transmit an optimum quantity of information in the available frequency band. To stabilise the local carrier generator on the carrier at the transmitter end, the carrier frequency is transmitted, for example, in conventional manner from the transmitter to the receiver through a separate transmission path or with the aid of a pilot signal added to the information pulse signals to be transmitted.

摘要翻译： 本发明涉及一种用于接收通过n相调制发送的信息脉冲信号的接收机，其中原始信息脉冲与来自一系列等距时钟脉冲的不同脉冲一致，该接收机包括一个n相解调器， 多个并行布置的同步解调器，其由具有相互不同的参考相位的载波馈送，所述基准相源自本地载波发生器，该本地载波发生器在与所接收的信号相关联的载波上同相稳定，信号信道连接到n相解调器的输出 包括由本地时钟脉冲发生器控制的采样电路，其采样电路表征相对于本地时钟脉冲的时刻的本地载波的相关参考相位的接收载波的相位的输出信号，接收器还提供组合 连接到采样卡的电路 电路，这些组合电路通过信号通道的输出的单独组合在相位图中表征发射信号的n个可能的相位扇区中的每一个。

公开(公告)号：US3307152A

公开(公告)日：1967-02-28

申请号：US28463563

申请日：1963-05-31

申请人： GEN ELECTRIC

发明人： BRIDGERS ROBBINS FLOYD

IPC分类号： G06F3/06 ,  G06F13/38 ,  H04L5/12 ,  H04L13/08 ,  H04L27/00 ,  H04L27/227

CPC分类号： H04L13/08 ,  G06F3/0601 ,  G06F13/38 ,  G06F2003/0698 ,  H04L5/12 ,  H04L27/2273 ,  H04L2027/0028 ,  H04L2027/0048 ,  H04L2027/0067